I have copied the T55N0JXUVPKEN17400.apk to a TC55, installed this APK and then run the EnterpriseEnabler, when prompted to Enable Enterprise Permissions, I tap on the button and then the device reboots.

In addition, EnterpriseEnabler is only for GMS build.Though it is no harm to apply it on professional configuration (non-GMS build), EnterpriseEnabler will check the OS version that device is running in recovery mode and skip to do anything if the running OS is non-GMS version.